Opened 3 years ago
Closed 2 years ago
#15201 closed defect (fixed)
Problem with Hecke eigenvalues with the same index as the level
Reported by:  fstromberg  Owned by:  

Priority:  major  Milestone:  sage6.2 
Component:  modular forms  Keywords:  
Cc:  Merged in:  
Authors:  Alex Ghitza  Reviewers:  Peter Bruin 
Report Upstream:  N/A  Work issues:  
Branch:  56341a3 (Commits)  Commit:  56341a3580c8f63a7e5b32e34325e23b021efc99 
Dependencies:  Stopgaps: 
Description (last modified by )
It seems to be a problem to compute Hecke eigenvalues for Modular Symbol subspaces at integers dividing the level N unless the eigenvalue for the Hecke operator at N is computed first. I have verified this problem for sage versions between 5.8 and 5.12.beta.
Example
sage: M=ModularSymbols(5,6,sign=1) sage: S=M.decomposition() sage: f=S[0] sage: f.eigenvalue(10) IndexError Traceback (most recent call last) ... IndexError: n must be a positive integer sage: f.eigenvalue(5) 25 sage: f.eigenvalue(10) 50
Change History (7)
comment:1 Changed 3 years ago by
 Milestone changed from sage6.1 to sage6.2
comment:2 Changed 3 years ago by
 Description modified (diff)
comment:3 Changed 3 years ago by
comment:4 Changed 3 years ago by
 Branch set to u/AlexGhitza/ticket/15201
 Created changed from 09/16/13 00:00:39 to 09/16/13 00:00:39
 Modified changed from 04/24/14 14:02:50 to 04/24/14 14:02:50
comment:5 Changed 3 years ago by
 Commit set to 56341a3580c8f63a7e5b32e34325e23b021efc99
 Status changed from new to needs_review
New commits:
56341a3  fix Hecke eigenvalues recurrence

comment:6 Changed 3 years ago by
 Component changed from number theory to modular forms
 Reviewers set to Peter Bruin
 Status changed from needs_review to positive_review
comment:7 Changed 2 years ago by
 Branch changed from u/AlexGhitza/ticket/15201 to 56341a3580c8f63a7e5b32e34325e23b021efc99
 Resolution set to fixed
 Status changed from positive_review to closed
Note: See
TracTickets for help on using
tickets.
The code used the recursive formula for the Hecke eigenvalues of ppower index without implementing the base case. This is fixed in the attached branch.